EP0893313B1 - Safety belt reeling device - Google Patents

Description

The invention relates to a device according to the preamble of claim 1.

Such a device known from US-A-4,534,441 to roll up a seat belt has a between Winding shaft and electric motor arranged gear, which in different depending on sensor signals Switch positions can be controlled. In the different Switch positions become the seat belt slack of the seat belt set depending on certain driving situations.

In a known from DE-A-43 32 205 The device is the one supplied by the electric motor in a three-point seat belt system Torque to improve webbing comfort when seat belt is on and to achieve a pre-tensioning function below that for the performance tightening critical limit applied ..

The object of the invention is to provide a device of the type mentioned in the introduction, which in a structural unit is that of a seat belt system, in particular a three-point seat belt system, required functions universally fulfilled.

This object is achieved by the characterizing features of claim 1.

Using a computer-assisted evaluation of the sensor signals, the Invention a universal implementation of a seat belt system in one Functions required by the motor vehicle. These functions are performed by one unit fulfilled, which includes the belt retractor. Integration in a belt retractor Unit succeeds in that the gear assume three different gear shift positions can. At the first gear shift position, the belt strap comfort is adjusted, in a second gear shift position, the setting of the belt force limit, and in a third gear shift position, the tensioning of the belt can be performed. The engine torque is used to achieve the various functions exploited. The electric motor used is preferably a flat motor trained, as described for example in DE-A-43 02 042. This electric motor can be interposed on one side of the belt retractor be arranged on the frame. The different gear shift positions can with the help of one or more adjustment elements, e.g. pyrotechnic control elements or Electromagnets that are controlled by the computer-aided evaluation device, can be set.

The first gearshift position can be used as a function of achieving belt strap comfort of sensor signals indicating belting or belting in the first switching position can be controlled. This works in this gear shift position Torque of the electric motor to the return force of the existing ones on the belt retractor Mainspring. This can be done in such a way that the mainspring operating point is adjusted becomes. The parking position of the seat belt, i.e. the completely on the winding shaft rolled up webbing length is a defined starting position. Starting from this The starting position can be the unwound length of the belt strap up to the belt point are recognized and a corresponding sensor signal is generated. Dependent on from this sensor signal indicating the belt point is transmitted by the electric motor the outer mainspring suspension, i.e. the base with which the Mainspring supported against the vehicle, adjusted. For example, this Mount point in a ring, which is proportional to the unwound Belt length is adjusted until the desired comfort wearing point is reached. This adjustment movement is from the electric motor to the first switching position set gearbox delivered.

When belting, which is detected by a sensor signal, for example, from the belt buckle is determined, the electric motor receives a rewind signal through which the outer suspension point of the spring is turned back to the starting position, see above that a strong driving spring retraction torque is exerted on the winding shaft and the webbing becomes. The electric motor can also add torque to increase the retraction force acting on the belt.

The desired retraction torque for comfort can occur during normal Driving operation also by a permanent torque control by the electric motor is continuously adjusted via the gear set to the first shift position become. This can be done, for example, by comparing the respective actual value of the Comfort carrying torque with, for example, in the central evaluation device stored setpoint for this torque.

In the second gear shift position, the one supplied by the electric motor Torque a belt force limiter, which is preferably between the frame or frame or fixed elements and the winding shaft acts. On such a belt tension limiter is described for example in DE-A-196 40 842. The belt force limiter is based on being exerted by the belt pulling force Energy generated by the forward body of the seated vehicle occupant is partially absorbed by the friction of parts moving against each other becomes. When a threshold is exceeded, the part of the winding wave moves, on which the webbing is wound, compared to one in particular part supported and held on the frame of the belt retractor, in the belt force limiter energy is absorbed or converted into heat by friction. The load or force limiting behavior is preferably based on a or several current parameters, such as the weight of the belted person to be secured and / or position of the vehicle seat, in particular in the longitudinal direction of the vehicle, and / or the severity of the accident, for which the change in acceleration is a parameter can be determined, e.g. can be set by map control. For this be Corresponding sensor signals are generated that work in the central computer-aided Evaluation device entered and evaluated there for the control.

For this purpose, the weight of the vehicle occupant can be used when getting into the seat belt with the help of appropriate measuring devices and, if necessary, his sitting position be detected in the vehicle seat. Taking advantage of the sensor signals obtained the belt limiter can then be preset.

Furthermore, the setting of the belt force limiter by early accident detection, in particular with the help of pre-crash sensor signals. As an additional Signal generators can also use a sensor signal that detects the brake pedal actuation become. The force limiter can be readjusted depending on the severity of the accident even during the accident due to the electric motor torque, which can then also be transferred directly to the winding shaft, if necessary, respectively.

The belt force limiter is preferably set reversibly and repeatably. For this purpose, a rotary movement generated by the electric motor can move into a direction relative to the winding shaft axis parallel adjustment movement, for example with the help of a thread engagement, which has an adjusting element set in rotation by the electric motor.

In the third shift position of the gearbox, the one supplied by the electric motor can Torque for tightening the webbing are transferred to the winding shaft. The third shift position of the transmission is activated by a sensor signal which, for example is generated by a crash sensor of conventional design. At this third Switch position can also be a pretensioning, as described in DE-A-43 32 205 is to be effected. Furthermore, the third switching position can then be set if the belted vehicle occupant is in an out-off position on the vehicle seat, for example an extremely forward or laterally inclined position, e.g. while sleeping. A torque can then be generated by the electric motor by which the vehicle occupant is pulled back into a normal sitting position becomes. This positioning tightening is a reversible process that repeats can be. This also gives the vehicle occupant noticeable security taught.

This tightening of positioning is of considerable advantage if the early detection of an accident is used indicating sensor signals. Such sensor signals can by Proximity sensors can be obtained using the vehicle speed. The vehicle occupant then becomes aware of any eventuality before or at the start of the accident Out-off position brought into a position optimized for the accident.

It is also possible to tighten the electromotive belt in the third switch position with overload, especially in the event of a serious accident due to the transmitted engine torque trigger. This is a one-time overload retraction on the webbing exercised. This creates very strong webbing retraction forces for a short period of time generated. This measure is also in the event of a second collision or vehicle rollover advantageous. U.U. In this application, the electric motor can be overloaded be destroyed.

Depending on the respective shift positions of the transmission and the sensor signals, which are delivered to the computer-supported central evaluation device , the respective torque generated by the electric motor can be set. For this purpose, the current intensity supplied to the electric motor is set accordingly.

In a further embodiment of the invention, an electric motor with two output shafts used. The electric motor can depend on the particular Driving situation, in particular controlled by the central control device (CPU) become. Here, the control takes place so that a of the first output shaft Adjustment of the force transmitted from the mainspring to the winding shaft, in particular Restoring force is caused and a driving force in from the second output shaft Winding direction is transmitted. The first output shaft of the electric motor is in preferably on the mainspring, which is provided on one side of the winding shaft. In this case, comfort adjustment of the fastened seat belt is preferably achieved. The rotary movement of the first output shaft of the electric motor can be via a suitable gearbox, which has a permanent drive connection between the output shaft and the mainspring is manufactured, transmitted. This gearbox can be a Belt transmission or gear transmission. The first output shaft acts preferentially on the suspension point of the mainspring at the end, which is opposite lies to the end of the spring, which is connected to the winding shaft. By adjusting the Attachment point, which on the gearbox and the electric motor on the belt retractor frame is supported, a comfort adjustment of the wearing comfort of the fastened seat belt can be carried out to reach.

The second output shaft of the electric motor preferably engages with the Driving spring on the opposite side to the winding shaft. The transfer of the Driving force of the second output shaft on the winding shaft can be via a gear, which is preferably designed as a gear transmission. The gearbox is more preferred Formed so that it by the drive movement of the second output shaft is automatically brought into the engaged position, so that the output shaft is brought into drive connection with the winding shaft.

The two output shafts of the electric motor can have separate, respectively assigned Anchors connected and designed as separate output shafts of the electric motor his. In a preferred manner, however, a motor shaft is used, the front of which protruding shaft ends form the first and second output shafts. This Motor shaft is connected to a motor armature.

By the second output shaft, the winding shaft can preferably after Loosening the buckle in the winding direction are driven so that the webbing is brought into its parking position. This can be done by loosening the buckle a corresponding signal for the control of the electric motor can be generated.

Furthermore, it is possible for the winding shaft to be driven by the second output shaft of the electric motor in the winding direction for a pre-crash tightening of the belt. For this can, for example, when activating the ABS system of the vehicle Signal are generated. However, such a signal can also be dependent are generated by a certain actuation pressure on the brake pedal. In dangerous This pre-crash tightening of the belt strap makes driving situations for the driver achieved additional security.

In the embodiment in which a single rigid through motor shaft is used is, the end of the shaft stub projecting the two output waves form, is when winding the webbing for tightening or for returning the webbing in its parking position on the spring side of the suspension point Spring moved so that the restoring force of the mainspring is increased. This will make the desired function of returning the webbing to its parking position or the Belt tensioning function not impaired. By increasing the restoring force the mainspring has an effect supporting these functions.

The second output shaft is preferably decoupled from the winding shaft, when the first output shaft carries out the comfort adjustment on the spring side. Furthermore, the belt length unwound from the winding shaft can be interrogated be carried out, the control of the drive of the respective output shaft takes place depending on the length of the webbing unwound.

For scanning or querying the length of webbing unwound from the winding shaft can rotate with the winding shaft at a reduced speed Interrogation device can be provided which is dependent on the respective webbing length Assumes the angular position. For example, one of the DE-A-43 14 153 used for a child lock wobble mechanism can be used with a gear ring. The eccentric to the winding shaft axis arranged gear ring, which with a seated on the winding shaft axis Gear meshes as a rotating rotating interrogator, which is a rotational angle position dependent on the respective unwound webbing length occupies. An electrical signal proportional to the respective angular position can be generated for the central control device (CPU).

Fig. 1

ein Blockschaltbild eines Ausführungsbeispiels der Erfindung;

Fig. 2

eine erste Ausführungsform eines Multifunktionsgurtaufrollers;

Fig. 3

Komfortprinzipkurven, welche die Aufrollkraft für einen Gurtbandauf- und -rückzug in Abhängigkeit von der auf der Wickelwelle aufgewickelten Länge wiedergeben;

Fig. 4

Darstellungen zur Gewinnung eines Kennfeldes der Gurtkraft zur Einstellung eines Gurtkraftbegrenzers;

Fig. 5

Belastungskurven des zeitlichen Gurtbelastungsablaufs auf eine verunfallte Person bei einem Gurtautomaten ohne Lastbegrenzer und bei Anwendung eines Lastbegrenzers, der im Ausführungsbeispiel der Erfindung ist;

Fig. 6

eine perspektivische Darstellung eines weiteren Ausführungsbeispiels der Erfindung an der Federseite des Gurtaufrollers;

Fig. 7

eine Seitenansicht der Federseite des Ausführungsbeispiels der Fig. 6;

Fig. 8

eine perspektivische Darstellung des Ausführungsbeispiels der Fig. 6 an der anderen Seite des Gurtaufrollers; und

Fig. 9

eine Seitenansicht der zur Federseite entgegengesetzt liegenden Gurtaufrollerseite; und

Fig. 10

eine Frontansicht des Ausführungsbeispiels.

The invention is explained in more detail with reference to the figures. It shows:

Fig. 1

a block diagram of an embodiment of the invention;

Fig. 2

a first embodiment of a multifunction belt retractor;

Fig. 3

Comfort principle curves, which represent the retraction force for a webbing up and down depending on the length wound on the winding shaft;

Fig. 4

Representations for obtaining a characteristic diagram of the belt force for setting a belt force limiter;

Fig. 5

Load curves of the temporal belt load sequence on an accident victim in an automatic belt device without a load limiter and when using a load limiter which is in the exemplary embodiment of the invention;

Fig. 6

a perspective view of another embodiment of the invention on the spring side of the belt retractor;

Fig. 7

a side view of the spring side of the embodiment of Fig. 6;

Fig. 8

a perspective view of the embodiment of Figure 6 on the other side of the belt retractor. and

Fig. 9

a side view of the belt retractor side opposite to the spring side; and

Fig. 10

a front view of the embodiment.

As shown in FIG. 2, the device for rolling up a seat belt webbing is included which, in addition to the belt retractor function, also a belt strap carrying function, a force limiter function and a pretensioner function can be exercised in a belt retractor integrated unit integrated. This unit has a winding shaft 1, on which a webbing 32 in a known manner between shaft flanges 8 around a winding shaft axis 19, e.g. when belting, is wound up and unwound when putting on the belt becomes. In a conventional manner, a drive spring 9 acts on the winding shaft 1 Retraction force by which the winding shaft is driven in the webbing winding direction becomes. The mainspring 9 acts via an inner suspension point designed as a spring heart 17, which with the winding shaft 1, in particular an adjusting part to be explained 21 on the left side of the winding shaft, preferably rigidly connected to the Winding shaft. In order to achieve the belt retractor functions, a sensor-operated retractor mechanism 20 can be provided, which in the case of excessive accelerations Vehicle-sensitive and / or webbing-sensitive for blocking the winding shaft 1 and in particular at least one of the two adjustment parts 21 on the frame 3 can be activated. This retractor mechanism 20 of the belt retractor can on the winding shaft side, on which an electric motor 2 and a gear 4 are provided, or between the mainspring 9 and the winding shaft 1 may be arranged.

The electric motor 2 is designed in a flat design and can have a structure such as that used, for example is known from DE-A-43 02 042. A motor shaft 11, which is guided out of the center of the motor structure of the electric motor 2, is aligned with the Winding shaft axis 19. The motor shaft 11 has a shaft extension 15 which axially through an axially extending bearing part 33 and thus the shaft body of the Winding shaft 1, the spring heart 17 and the drive spring 9 is passed. The shaft extension 15 is rigidly connected to the motor shaft 11 at one end. On her other At the end, it is connected to an actuator 10, with which an external suspension point 16 of the mainspring 9 by rotation about the winding shaft axis 19 or axis of The spring heart 17 can be adjusted in its position, as will be explained in detail later can.

Between the shaft part on which the webbing 32 between the two shaft flanges 8 is wound up and that in normal belt retractor operation with the winding shaft 1 adjustable part 21 is a belt force limiter 5, for example in the form a multi-plate clutch. In the exemplary embodiment shown in FIG. 2 is a plate pack of the belt force limiter 5 on both sides of the winding shaft 1 provided between the shaft flanges 8 and the axially displaceable adjusting part 21. Such a belt force limiter is described in DE-A-196 40 842. to Setting the belt force limit is the torque of the electric motor 2, as in individual will be explained on the axially displaceable relative to the winding shaft 1 Transfer setting part 21. Due to the axial displacement of the adjustment part, the load or force limiting behavior of the belt force limiter 5 depending on the suitable sensor signals, in particular occupant weight, seating position, accident severity and, if necessary, brake pedal actuation, as will be explained in more detail below.

To achieve the penalty effect, the torque of the electric motor 2 is also transmitted to the winding shaft 1 via the gear 4. The gear 4 essentially consists from two gear wheels, namely a first gear wheel 13 with teeth 39 and a second gear wheel 14 with teeth 40 which are different Axles 34 and 35 are rotatably mounted on the frame 3. The first gear 13 is standing in meshing 37 with one of the electric motor 2, optionally via a clutch connected drive gear 12. The drive gear 12 can on the already mentioned Coupling that can be activated by axially or radially adjustable coupling elements is, or rigidly connected to the motor shaft 11. The second gear 14 which can also be designed as a toothed wheel, is in tooth engagement 36 with a Adjusting nut 22, which is connected to the adjusting part 21. By means of the an axial displacement takes place in the second gear wheel 14 the adjusting nut 22 and thus the adjusting part 21, as described in detail in DE-A-196 40 842 is described. As a result, the load or force limiting behavior of the Belt force limiter 5 set. The adjusting nut 22 is through a thread engagement 47 on the bearing shaft 33 penetrating and supporting the winding shaft 1, which on Frame 3 is supported, axially displaceable.

In the embodiment of FIG. 2, the two gear wheels 13 and 14 are on the frame 3 rotatably mounted about the axes 34 and 35.

Furthermore, at least one of the two shaft flanges 8 has an outer ring gear 41, a rotary drive connection with the first gear wheel 13 or a blockage produce the winding shaft rotation, as will be explained in more detail.

The mode of operation of the illustrated embodiment is as follows:

The gear 4 can be brought into three different shift positions. In the first The belt shifting comfort can be adjusted for the gear shift position. In the the belt transmission force limit can be adjusted in the second gear shift position, and in the third switching position a tensioning function can be exerted on the winding shaft become. In order to implement the various gear shift positions, there are drive connection means and blocking devices provided with which between the Gear rings 39, 41 and 40 of the gear wheels 13, 14 and on the winding shaft flanges 8 rotary actuator connections and blockages can be performed. In the 2, a first setting means 23 is provided for this purpose two sprockets rotatably connected together rotatably about an axis 24 25 and 26. The first setting means 23 also has a blocking element in the form of a blocking tooth 31. This embodiment also has a second adjusting means 27 with two spaced apart from one another in a rotationally fixed manner connected sprockets 29 and 30, which about a common axis 28th are rotatable. The two setting means 23 and 27 can alternate with the teeth 30, 40, 41 of the gear wheels 13, 14 and the winding shaft 1 with the help of a controllable Actuator 38, the electromagnetic, electromechanical or works in a similar way.

The setting means 23 and 27 can be used as separately operable setting means or by means of a rocker can be formed about a rocker axis actuating adjustment. For actuation the setting means can be one or more controllable electromagnets or the like can be used.

The setting means 23 and 27 are used to set the first gear shift position out of engagement with the gear teeth 39 to 41 of the gear wheels and the winding shaft held. The torque of the electric motor 2 is in this switching position by the Transfer the motor shaft 11 to the actuator 10 via the shaft extension 15. This Gear shift position is caused when the corresponding sensor signals Belts or belts to a central computer-aided evaluation and control device 42 (CPU Fig. 1) is reported. When belting in depends on comfort principle curves (Fig. 3), which in one or more with the central evaluation and Control device 42 connected memories 44 are stored, an adjustment of the outer attachment point 16 of the mainspring 9 with the aid of the electric motor 2 delivered torque causes. The evaluation and control device 42 controls this the current supplied to the electric motor 2. Depending on the length of the webbing extension (Abscissa in Fig. 3), for which the device 42 also a corresponding Sensor signal is supplied, the outer suspension point is adjusted 16 to the retraction force or retraction force corresponding to the comfort wearing point (Ordinate in Fig. 3) of the mainspring 9 on the belt webbing is reached.

When belting, the evaluation and control device 42 is also switched on, for example Sensor signal tapped at the buckle, fed in. To on that on the winding shaft 1 webbing to be rolled up to apply an increased roll-up force outer suspension point 16 of the mainspring by rotation mediated by the electric motor 2 the actuator 10 returned to its starting position. The webbing is then completely wound up into its parking position on the winding shaft 1. Around the webbing in its parking position, however, it is also possible to close the below explanatory third switching position of the transmission 4 in which the drive rotary movement of the electric motor 2 via the gear wheels on the winding shaft 1 in the winding direction is applied. Figure 3 shows the winding forces in the dashed curves with webbing extension and retraction depending on the respective extension length without comfort and in the extended curves (comfort curves) with a comfort effect.

In the explained first gear shift position, the gear wheels 13 and 14 rotate freely With. The roll-up force required to roll the webbing into the park position is transmitted from the mainspring 9 via the spring heart 17 to the winding shaft 1. For the rotational movement of the winding shaft 1 in the frame 3 and with respect to that carried out Bearing part 33, roller bearings 18 are provided.

The second gear shift position is then set when the vehicle occupant is on has taken a seat in the vehicle seat and has fastened the seat belt. In the second gear shift position is in the embodiment of FIG. 2 by corresponding Control of the actuating device 38 by the evaluation and control device 42 brought the adjusting means 23 into engagement with the toothings 39, 40 and 41. This creates a rotary drive connection between the two gear wheels 13 and 14 via the non-rotatably connected gear rings 25 and 26. By blocking engagement of the blocking tooth 31 in the toothing 40 of the Winding shaft 1 becomes winding shaft 1 and the shaft flanges rigidly connected to it 8 blocked against rotation.

In this gear shift position, the rotary movement generated by the electric motor 2 via the two gear wheels 13 and 14 on the adjusting nut 22, which on the adjusting part 21 of the belt force limiter 5 acts for an axial adjusting movement. The axial positioning movement is controlled by the evaluation and control device 42 (Fig. 1). This receives sensor signals which are proportional to the weight of the Vehicle occupants are, as well as sensor signals, which determine the position of the vehicle seat specify lengthways in the vehicle. A presetting is made from these sensor signals the force limiting behavior of the belt force limiter 5 by corresponding Axial displacement of the adjusting nut 22 and the adjusting part 21 is made.

Furthermore, as is shown in FIG. 4, a map for the belt force can be generated, on the abscissa the webbing extension after tightening and on the ordinate the restraint force imparted by the belt strap is applied. The map is made namely three parameters gained the course of the accident, the occupant weight and the Seat position of the vehicle seat in the longitudinal direction of the vehicle. The parameters "Occupant weight" and "sitting position" result from an accident. The "Accident course" is with the help of one or more acceleration sensors, which the temporal course of the acceleration or Measure accelerations, recorded. Depending on the respective parameters each assigned force map in KN compared to the belt extension in mm and combined to the map of the belt force (KN) compared to the belt extension (mm). The map determination of the belt force is therefore final during the course of the accident and is adapted to this. This map is related to vehicle occupants in a memory 45 (Fig. 1) stored so that it can form a control signal at any time for the electric motor 2 by the evaluation and control device 42 stands. The adjustment movement is reversible, so that even during the accident depending on the severity of the accident, regulation of the power level of the Belt force limiter 5 is possible.

In the event of an accident, after the seat belt has been tightened, there is an occupant delay load achieved by the belt force limiter 5, which in FIG. 5 is shown. The timing of this delay load can be changed by appropriate Adjustment of the belt force limiter 5 achieved with the help of the electric motor 2 become. For this purpose, the electric motor is controlled by the evaluation and control device 42, control depending on that stored in a memory 46 the delay load takes place over time.

The central evaluation and control device 42 also provides one to the respective Vehicle seat, for example the passenger seat, associated airbag device 7 controlled. It can be taken into account here that the airbag device 7 is only above a certain vehicle speed, for example 60 km / h, which is a parameter for the severity of the accident is activated. The end of the belt force limit Retention effect (falling edge of the load curve shown in FIG. 5) arises if, for the assigned seat, in particular occupied seat, e.g. Passenger seat, one determined by the evaluation control device 42 from the sensor signals Airbag detonator signal is present and the body of the vehicle occupant advancing can dive into the inflated airbag after about 60 msec (Fig. 5). Through the evaluation and control device 42, the actuation of the airbag device 7 and the delay load of the Belt force limiter 5 coordinated in time. The upper load curve A in Fig. 5 corresponds to the belt force load without force limitation and the lower load curve B corresponds to the belt force limitation with belt force limiter.

In the third gear shift position in the embodiment of FIG. 2, the setting means 27 from the one controlled accordingly by the evaluation and control device 42 Actuator 38 actuated. This creates a rotary drive connection Made between the first gear 13 and the winding shaft 1. This The connection is made by the meshing of the two sprockets connected together 29 and 30 in the embodiment of FIG. 2 in the teeth 39 and 41st Through this connection, the torque generated by the electric motor 2 via the Gear wheel 13 and the adjusting means 27 (FIG. 2) are transferred to the winding shaft 1. This third gear shift position is set when by a crash sensor or a pre-crash sensor sends a corresponding signal to the evaluation and control device 42 is delivered. The device 42 then controls the actuating device 38 Actuation of the second setting means 27 (Fig. 2). By the pre-crash sensor signal early accident detection can be displayed. This signal can, for example are obtained from a proximity sensor with which relative speeds two vehicles driving in a row are found. The one from the multifunction belt retractor 6 existing unit is replaced by the third gear shift position in Brought punishment. It can also be a positioning tightening in the form of a slight retraction of the webbing by operating the electric motor 2 can be brought about. Such a positioning tightening can then also be carried out when an out-off sensor signal of the evaluation and control device 42 is forwarded. Such a signal is generated when the vehicle occupant has moved sideways from the normal sitting position, for example when sleeping. This signal can be generated, for example, by several sensors provided on the vehicle seat, which also record the occupant weight. By gentle tightening the seat belt can then bring the vehicle occupant back into the normal sitting position become. This positioning tightening can also take place if below the threshold of the vehicle speed change triggering the crash sensor signal a vehicle speed change takes place, so that a belt pretensioner or positioning tightening by the electric motor 2 on the winding shaft 1 is transmitted in the third gear shift position. Such a pretensioner is described in DE-A-43 32 205. The positioning tightening is reversible and can be repeated at any time depending on the driving situation.

After tightening, a blocking device with one or two blocking pawls 43 brought into locking engagement with the adjusting part 21, in particular on both sides of the winding shaft. For this purpose, the respective setting part 21 can have teeth on its outer circumference 48, in which the associated locking pawl 43, which in a known manner is controlled by the retractor mechanism 20 in a manner sensitive to the vehicle or the belt.

After this blocking intervention, the above occurs in the event of an accident explained with the second gear shift position and FIGS. 4 and / or 5 Belt force limit in action.

As already explained in connection with the regulation of the belt comfort, can after strapping the webbing by the generated by the electric motor 2 Torque are rolled up to the starting position, the third described last Gear shift position is used.

In the embodiment shown in Figures 6 to 10 are the same Components used the same reference numerals as in the embodiment described above.

In the embodiment shown in Figures 6 to 10, an electric motor 52 is used, which has two output shafts 49 and 50. The output waves 49 and 50 extend essentially parallel to the winding shaft axis 19 and are located itself on the two end sides of the essentially cylindrical electric motor 52. The electric motor 52 is, e.g. is shown in Fig. 10, on the frame 3 of the Belt retractor attached so that 52 attacking reaction forces on the electric motor the frame 3 are directed into the vehicle body.

The two output shafts 49 and 50 can be separate output shafts that are separate can be controlled by each other. Furthermore, separate drive systems for the output shafts, in particular associated motor anchors, with these Output shafts must be connected.

However, the two output shafts 49 and 50 preferably protrude Shaft ends of a continuous motor shaft 66 are formed (Fig. 10).

The first output shaft 49 is in constant drive connection via a belt drive 57 with a rotating part 58, which is firmly connected to the suspension point 16 of the mainspring 9 is. Instead of the belt drive 57, a gear transmission can also be used which the drive movement of the first output shaft 49 to the suspension point 16 of the mainspring 9 transmits.

The second output shaft 50 is on the opposite side of the electric motor 52. A first gear 53 sits on the second output shaft 50 in a rotationally fixed manner. This gear 53 meshes with a second gear 54. The gear 54 is over one Support 59 pivotally supported about the second output shaft 50. By a spring 60, which acts on the carrier 59, the gear 54 is disengaged from one third gear 55, which is rotatably connected to the winding shaft 1, pressed. The The direction of action of the spring 60 is shown in FIG. 9 by an arrow 61.

The drive connection between the second output shaft 50 and the winding shaft 1 is connected by the rotational movement, which from the output shaft 50 to the rotationally fixed Gear 52 is transmitted manufactured. The rotation of the gear 53 in the drive direction (arrow 62) is transferred to the second gear 54, at the same time a torque on the carrier 59 against the force of the spring 60 (arrow direction 61) is exerted so that the gear 54 is brought into engagement with the gear 55 (Fig. 9). In this way, the drive connection between the second Output shaft 50 and the winding shaft 1 manufactured. This couples when the engine is not running Gear 54 automatically turns off so that the drive connection between the output shaft 50 and the winding shaft 1 is separated.

However, the gear 54 can also be actuated by an actuating device 63, which is electromagnetic can work, be engaged and disengaged. For this purpose, the actuator 63 act on the support 59 via a push arm 64 and that Disengage and engage gear 54.

Through the one transmitted from the second output shaft 50 to the winding shaft 1 The webbing rewind function can be turned to the parking position of the webbing extension be performed. It is also possible to tighten a pre-crash if dangerous Driving situation, for example when the vehicle's ABS system is activated to perform. For this purpose, appropriate signals from the central Control device (CPU) 42 is processed and evaluated to control electric motor 52. For example, to bring the webbing back into the parking situation when releasing the buckle, a corresponding signal is generated, which, like described, is evaluated to control the electric motor 52. Then it will be the second output shaft 50 driven and the drive movement via the transmission, which is formed by the gears 53 and 55, transferred to the winding shaft 1. Precrash tightening also generates one when the ABS system is activated Signal evaluated by the CPU 42 and the electric motor for driving the second Output shaft 50 driven.

In particular for the webbing rewind function in the parking position of the webbing to receive a query of the length of the webbing unwound from the winding shaft 1, an interrogation device 51 is provided. In the illustrated embodiment of the 6 to 10, this interrogation device 51 is located on the left winding side which is the gear formed by the gears 53 and 55. The interrogator 51 can be eccentric to the winding shaft axis 19 and an axis 56 rotatable gear ring can be formed, as it from DE-A-43 14 153 for a child lock is known in a belt retractor. The transmission ring of the interrogator 51 is, for example, by an extension of the gear 55, the rotation sits on the winding shaft axis 19, driven with reduction. That way a wobble gear, in which the position of the gear ring, in particular the Angular position of the gear ring, a measure of the length of webbing unwound represents. This measure can be scanned electrically, electronically, optically or the like and for controlling the winding operation generated by the second drive shaft 50 can be evaluated in the central control device (CPU) 42.

On the spring side, a scanning device 65 can also be provided, which the Detects the end of the tape pull-out movement when putting on the seat belt and off which can also be used to derive the dimension of the unwound webbing length. In The adjustment then takes place depending on the length of the webbing being processed the comfort of wearing the seat belt.

For the comfort adjustment of the wearing comfort of the fastened seat belt is the first output shaft 49 on the side of the drive spring 9 connected to the rotating part 58, which has the hanging point 16 of the mainspring 9. The first drive shaft 49 stands over a gear, which is designed as a belt drive 47 in the exemplary embodiment is in constant drive connection with the rotating part 58. This drive connection can also be produced by a gear transmission. Also for comfort adjustment can the unwound webbing length determined by the interrogator 51 evaluated in the evaluation and control device 42 and a corresponding one Drive signal for the first output shaft 49 of the electric motor 52 are generated. at the first output shaft 49, e.g. by a no closer Blocking device shown or a short-circuit torque that the spring force counteracts, be blocked.

In this way, essential safety functions of the belt retractor can be used alone by controlling the electric motor 52, which is preferably on the belt retractor frame 3 is supported and fastened and thus a structural unit with the belt retractor forms, achieve.

Claims (32)

1. Device for retracting a seat belt webbing on a winding shaft (1) rotatably mounted in a frame (3) in a motor vehicle comprising an electric motor (2) which can be coupled to the winding shaft (1) in both directions of rotation and from which torques, which can be adjusted in dependence on certain driving situations, can be brought to act upon the winding shaft (1), a gear (4) arranged between the electric motor (2) and the winding shaft (1), which can be controlled in dependence on sensor signals in various switch positions, characterised in that, due to the motor torque, in a first gear switch position the belt webbing comfort in wear can be activated, in a second gear switch position the belt force limitation can be activated, and in a third gear switch position the belt webbing tightening can be activated.
2. Device according to Claim 1, characterised in that the gear (4) can be adjusted into one of the three switch positions.
3. Device according to Claim I or 2, characterised in that in a gear switch position, several different torques can be transferred onto the winding shaft (1).
4. Device according to one of Claims 1 to 3, characterised in that in the first gear switch position a spring retracting force acting upon the winding shaft (1) can be adjusted.
5. Device according to Claim 4, characterised in that a fixing point (16), against which a motive spring (9) acting upon the winding shaft (1) in the belt webbing retracting direction is supported at its one end opposite the frame (3), can be adjusted.
6. Device according to Claim 4 or 5, characterised in that the gear (4) can be directed into the first gear switch position in dependence on the sensor signal indicating the seat belt placement.
7. Device according to one of Claims 1 to 3, characterised in that in the second gear switch position a belt force limiter (5) acting between the frame (3) and the winding shaft (1) can be adjusted.
8. Device according to Claim 7, characterised in that the belt force limiter (5) can be adjusted during a crash and/or prior to the crash.
9. Device according to Claim 7 or 8, characterised in that the gear (4) can be directed into the second gear switch position after the seat belt placement and in particular after the adjustment of the belt webbing comfort in wear.
10. Device according to one of Claims 7 to 9, characterised in that in the second gear switch position, for the purpose of controlling the motor torque during the adjustment of the belt force limitation, an evaluation and control device (42) receives sensor signals, which indicate the occupant weight and/or the position of the motor vehicle seat within the motor vehicle and/or an early crash recognition and/or the severity of the accident and/or a brake pedal application.
11. Device according to one of Claims 1 to 3, characterised in that the gear can be directed into a third switch position, in which the torque of the electric motor (2) can be transferred onto the winding shaft (1) for a belt webbing retraction, during the tightening process.
12. Device according to Claim 11, characterised in that the torque of the electric motor (2) can be transferred with overload onto the winding shaft (1) in the third gear switch position.
13. Device according to Claim 11 or 12, characterised in that, for the purpose of controlling the motor torque, the evaluation and control device (42) evaluates sensor signals, which indicate a crash and/or an early crash recognition and/or an Out-Of-Position of the occupant and/or the removal of the seat belt.
14. Device according to Claim 11, characterised in that, for the purpose of tightening the seat belt, the motor torque can be transferred onto the winding shaft (1) prior to a locking engagement of a locking device (49) supported on the frame (3) in an adjustment part (21) of the force limiter (5).
15. Device according to one of Claims 1 to 14, characterised in that the restraining force exerted by the belt force limiter (5) is reduced in a controlled manner if an ignition signal is present for an airbag (7) assigned to the seat belt.
16. Device according to one of Claims 1 to 15, characterised in that the basic adjustment of the belt force limiter (5) is dependent on the occupant weight and the seating position of the occupied vehicle seat.
17. Device for retracting a seat belt webbing on a winding shaft rotatably mounted in a frame in a motor vehicle comprising an electric motor which can be coupled to the winding shaft and from which torques, which can be adjusted in dependence on certain driving situations, can be brought to act upon the winding shaft according to one of Claims 1 to 16, characterised in that the electric motor (52) can be controlled in dependence on each driving situation and comprises two output shafts (49, 50), of which a first output shaft (49) is used to adjust the force transferred from the motive spring (9) onto the winding shaft (1) and of which a second output shaft (50) transfers a drive force onto the winding shaft (1) in the winding direction.
18. Device according to Claim 17, characterised in that the second output shaft (50) engages the winding shaft (1) at the side opposite the motive spring (9).
19. Device according to Claim 17 or 18, characterised in that the two output shafts (49, 50) are arranged parallel to the winding shaft axis (19).
20. Device according to one of Claims 17 to 19, characterised in that in each case only one of the two output shafts (49, 50) is driven.
21. Device according to one of Claims 17 to 20, characterised in that during the drive of the first output shaft (49) the drive connection between the second output shaft (50) and the winding shaft (1) is interrupted.
22. Device according to one of Claims 17 to 21, characterised in that the two output shafts (49, 50) are shaft ends of a continuous motor shaft (66).
23. Device according to one of Claims 17 to 22, characterised in that the belt webbing length unwound from the winding shaft (1) can be monitored.
24. Device according to Claim 23, characterised in that for determining in each case the unwound belt webbing length, a monitoring device (51), co-rotating with the winding shaft (1) at a reduced rotational speed, is foreseen, assuming a rotational angle position dependent in each case on the unwound belt webbing length.
25. Device according to one of Claims 17 to 24, characterised in that the drive of the first output shaft (49) and/or the second output shaft (50) is controlled in dependence on the belt webbing length unwound from the winding shaft (1).
26. Device according to one of Claims 17 to 25, characterised in that the comfort in wear of the worn belt webbing (32) can be adjusted by the first output shaft (49).
27. Device according to one of Claims 17 to 26, characterised in that the winding shaft (1) can undergo a pre-crash belt tightening in dependence on the activation of an ABS system of the vehicle by means of the second output shaft (50).
28. Device according to one of Claims 17 to 27, characterised in that the first output shaft (49) is in a constant drive connection with the fixing point (16) of the motive spring (9).
29. Device according to one of Claims 17 to 28, characterised in that the second output shaft (50) can be coupled to the winding shaft (1) via a gear which can be connected by the drive movement of the second output shaft (50).
30. Device according to one of Claims 17 to 29, characterised in that the electric motor (52) is supported on the retractor frame (3).
31. Device according to one of Claims 17 to 30, characterised in that the first output shaft (49) can be locked in the case of an adjusted level of comfort in wear.
32. Device according to one of Claims 18 to 31, characterised in that during the drive of the winding shaft (1), the fixing point (16) of the motive spring (9) is also adjusted by the second output shaft (50) in the webbing retraction direction in the sense of a spring force increase.

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